International Arid Lands Consortium Supports Investigations Into Sustainable Use of Dryland Oaks in Israel and the United States

Water Use and Growth in Dryland Oaks: Effects of Coppice Thinning

November 21, 2000 (Tucson, AZ)--Management of dryland oaks for sustainable use is of increasing importance to people in Israel and the southwestern United States. Trees in these woodlands are easily subjected to over-cutting for fuel and other wood products and to overgrazing. Management of dryland oaks is changing in both countries, however, with an increasing emphasis on sustaining these species in a holistic, ecosystem-based manner. The International Arid Lands Consortium (IALC) supports research to provide basic information about plant-water relationships of these trees in woodlands that are subjected to manipulation, or deliberate human action to maintain and harvest these trees.

Researchers from Israel and the southwestern United States are expanding the results of earlier work focused on developing the necessary methodology to obtain initial estimates of water use by mature trees and sprouts on a daily and seasonal basis. The information gained during these earlier studies has provided preliminary information useful for evaluating tradeoffs between water use and plant productivity when developing strategies for managing tree and sapling stands.

The scientists, from the Desert Research Institute-Nevada and Ben Gurion University-Israel, are continuing to study how deliberate thinning of oak thickets, or coppices, increases growth rates and production of oak trees for fuel and other uses. This two-year study is being conducted in Israel and the United States. Researchers are determining how increases in growth rates and production relate to water use by the specific species of oak trees and shrubs. This knowledge will help land managers optimize, to the extent possible, the use of the limited water available for plant growth.

The core of the field work involves measurement of the velocity of sap flow on daily and seasonal bases. These measurements then are translated into estimates of water use by oak trees for the respective time periods. Thinned and unthinned coppice are compared. The data accumulated about water use values for the sampled situations can ultimately be extrapolated to conditions that are common to the woodlands in both countries. Source data will also be used in simulation models of water flow through woodlands ecosystems.

Support for this project came from the USDA Cooperative State Research, Education, and Extension Service.

 

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The International Arid Lands Consortium (IALC) is an independent nonprofit organization dedicated to exploring the problems and solutions unique to arid and semiarid regions. IALC promotes cooperative research and practical application of new knowledge to develop sustainable ecological practices. The member institutions and their affiliates share a mission to enable people of arid lands to improve the quality of life for future generations. IALC members include the University of Arizona, Desert Research Institute-Nevada, the University of Illinois, Jewish National Fund, New Mexico State University, South Dakota State University, Texas A&M University-Kingsville, and the Higher Council for Science & Technology-Jordan. The Ministry of Agriculture & Land Reclamation-Egypt is an affiliate member.

Project Addressed in this News Release:

  • 99R-01 Water Use and Growth in Dryland Oaks: Effects of Coppice Thinning (The University of Arizona, The Agricultural Research Organization-Israel, USDA Forest Service Rocky Mountain Research Station)